Feeder drive assembly and replaceable section for tape supplying and cover peeling

ABSTRACT

A cassette-like supply and peel assembly of a tape feeder, comprising the support and guide for an electrical component supply tape and the mechanism for peeling a cover from the tape, is removably interconnectable with a drive assembly which provides motive power to the peeler and stepwise feeding of the tape. The length of the feeding steps is adjustable according to the center-to-center distances between components, which can vary from tape to tape. An operator can adjust the step length from the rear of the feeder by varying one limit of a stroking length of the feeder.

PRIOR ART CROSS REFERENCES

U.S. Application Ser. No. 861,977 (now U.S. Pat. No. 4,735,341),Hamilton, et al, IMPROVED FEEDER FOR ELECTRICAL COMPONENT SUPPLY TAPES,filed May 12, 1986.

U.S. Pat. No. 4,494,902, Kuppens, et al, METHOD OF AND DEVICE FORFEEDING ELECTRIC AND/OR ELECTRONIC ELEMENTS TO GIVEN POSITIONS, issuedJan. 22, 1985.

U.S. Pat. No. 4,620,655, Fujita, APPARATUS FOR SUPPLYING TAPED PARTS,issued Nov. 4, 1986.

U.S. Pat. No. 4,606,117, Takahashi, et al, APPARATUS FOR AUTOMATICALLYMOUNTING CHIP TYPE CIRCUIT ELEMENTS ON PRINTED CIRCUIT BOARDS, issuedAug. 19, 1986.

Japanese Patent Disclosure No. 61-64199, laid open Apr. 2, 1986.

BACKGROUND OF THE INVENTION

The invention is in the field of tape feeders in general by which a tapeis advanced stepwise to sequentially present components to a pick-upstation where the component is removed from the tape for subsequenthandling, such as transfer to a conveyor or a circuit board.

Particularly, the invention is directed to feeders for stepwise indexingof tapes having pockets containing surface mountable electricalcomponents. Typically, a top cover of the tape is peeled sufficientlyfrom the substrate so as to open each pocket in turn, and thus provideaccess to the component therein. Auxiliary covers or movable "shutters"often are provided to prevent loss of components from opened pockets.

Several types of supply tapes are used presently, and the invention isapplicable to these and other component supply tapes. One tape has aplastic substrate embossed to define component holding pockets which areenclosed by a separable thin plastic top cover; another tape has holesall the way through a cardboard substrate with top and bottom covers forthe holes so as to define the component pockets.

The prior art cross-referenced above generally discloses peeling of thetape cover by indexing a take-up reel along with indexing of thecomponent supply tape, wherein the cover is passed around a fixed guidesurface and maintained under tension by the take-up reel. Although theapparatus of the invention is particularly adapted to a peelingmechanism which is different from these cross-references, the conceptsof step length adjustment and interchangeable supply and peel assembliesof the invention are equally adaptable to the prior art.

The majority of the prior art tape feeders utilize indexing wheelshaving pins on the periphery thereof which are engagable in the indexingholes of the supply so as to feed the tape stepwise by rotation of thewheel. Such stepwise rotation is usually accomplished by means of a rackand pawl-type of arrangement wherein the pawl is engaged in a tooth ofthe rack and moved to advance the rack by one indexing step. Heretofore,the stepping length of indexed feeding by the wheel has been adjustableby removing and relocating a pin which determines whether the pawlengages every rachet tooth or every other rachet tooth. Rather thanskipping a rachet tooth to increase the length of feeding step, theprior art has also engaged two consecutive rachet teeth by the pawl, foreach step, such that each step actually comprises two half steps.

It is also known to have a belt driven indexing wheel driven by a motorwherein a bit switch of a circuit board is selected to determine anumber of revolutions of the motor per indexing step.

In the industry involved, tape feeders are generally "bricked" togetherside-by-side to provide the maximum amount of feeders in a minimumamount of space and generally it is necessary to remove a feeder inorder to change the stepping length and/or the supply tape. If a jam orbreakage of the tape occurs with the prior art, it also generally isnecessary to remove and replace the entire feeder assembly or to shut itdown for an uneconomical length of time necessary to clear the jam or torethread the tape in the feeder and/or the cover material into thepeeler.

The instant invention overcomes these various problems in a uniquemanner, and these and other advantages and objectives of the instantinvention will become apparent from the following detailed disclosure.

SUMMARY OF THE INVENTION

A top cover is peeled from a component supply tape by passing the coveraround a guide surface and in a peeling direction generally reverse tothe feeding direction of the supply tape while moving the guide surfacein the peeling direction in order to minimize the tension necessary toaccomplish the peeling.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation of an apparatus of the invention.

FIG. 2 is a top plan view of the device of FIG. 1.

FIG. 3 is a left side elevation of the device of FIG. 1.

FIG. 4 is a rear elevational view of the device of FIG. 1.

FIG. 5 is a cross section of FIG. 1, as viewed generally in thedirection of arrows 5--5.

FIG. 6 is an enlargement of a portion of FIG. 1, with portions thereofremoved and/or broken away.

FIG. 7 is a front elevation of the device of FIG. 1, illustrating theseparability of the major portions of the device.

FIG. 8 is an isometric view of the tape guide plate and attached peelerarm.

FIG. 9 is an exploded isometric view of the device of FIG. 8.

FIG. 10 is an isometric view of the bottom of the tape guide plate.

FIG. 11 is an exploded isometric of the square motion indexer assembly.

FIGS. 12 and 13 are enlarged, partial top plan elevations illustratingthe extreme extended and retracted positions of the peeling guide andshutter.

FIGS. 14--16 are partial front elevations illustrating the tape feedingand cover peeling operations.

FIG. 17 is a top plan view of the device of FIG. 18.

FIG. 18 is a partial elevational view illustrating an alternateembodiment of spring biasing the peeler guide to the extended position.

FIG. 19 is a partial isometric view illustrating a component supply tapewith pocketed substrate, cover therefor, and component carried thereby.

DETAILED DESCRIPTION OF THE INVENTION

As seen in FIG. 19, a typical component supply tape 2 comprises asubstrate 3 having indexing or feeding holes 6 along an edge thereof andpockets 4 in which surface mountable electrical components 9 arereceivable. A cover 8 of "MYLAR" or the like retains the components 9within the pockets 4.

Referring to FIGS. 1--7, a loaded supply tape 2 enters the feeder (onthe left a viewed in FIG. 4) for incremental feed of each pocket 4thereof to a pick-up station. The covering material 8 is removedsequentially from each pocket 4 so as to provide access for a vacuumspindle or other means of retrieving each component out of an openedpocket. After being peeled from substrate PG,8 3, covering material 8 isstuffed into a scrap box 72 in a manner yet to be described. As seen inFIGS. 1 and 7, the base 12 of the feeder drive assembly 10 has a guidechannel 24 through which the empty substrate 3 is redirected from thefront or forward end of the feeder (the left end as viewed in FIG. 1)toward the rear of the feeder (the right end as viewed in FIG. 1). Acutter 25 (FIG. 6) may be provided to sever the empty substrate 3 at apoint just after the pick-up station so as to facilitate interchangingof supply and peel assemblies 50 with a drive assembly 10, as may bebetter understood by referring to FIG. 7.

As seen in FIG. 6, a backing member 30 is biased by spring metal member31 into engagement with the underside of a tape pocket 4 which issituated at the pick-up station in order to ensure good contact of thevacuum spindle with the component 9 during pick-up thereof. Member 30may also have an ejection pin 32 for penetrating the bottom of a pocketand overcoming static electricity or the like which might hinderretrieval of a component 9 from the pocket 4. Ejector pin 32 is normallybiased downwardly by a spring or the like and is extended into a pocket4 of the substrate 3 by means of fluid pressure through hose 324.

Referring to FIGS. 6, 11 and 14--16, the tape 2 is advanced or fedincrementally by raising feed pins 38 so as to engage them in indexingholes 6 of substrate 3, whereafter feed pins 38 are displaced to theleft from the position of FIG. 15 so as to advance the tape to the left.Then, feed pins 38 are withdrawn from the indexing hole of the substrateand moved to the right (as viewed in these Figures) before again beingraised into engagement with other indexing holes 6 in preparation foranother cycle of indexed feeding. Thus, feed pins 38 are moved back andforth and up and down in a sequence which describes a counterclockwise,square path of travel.

A particular advantage of the apparatus of the invention is that atleast sideways the forward and backward movement of the feed pins 38 isprovided by pneumatic cylinder 22 so that the stroke or back and forthdisplacement of feed pins 38 may be controlled by an adjustable stop 20.

The square motion indexing assembly 33, which supports feed pins 38,includes a plate 16 which is slidably supported by wheels 14 (best seenin FIG. 6), with slide support 16 being connected to piston rod 23 ofcylinder 22 for movement back and forth according to actuation ofcylinder 22. A forward stop 18 ensures the location of a pocket at thepick-up station at the end of forward stroking, and rearward stop 20 isadjustable by a screw 21 or the like to change a limit of the strokinglength and provide that drive assembly 10 (as seen in FIG. 7) canaccommodate supply and peel assemblies 50 (also seen in FIG. 7) whichrequire indexing steps of different lengths. This is particularlysignificant since supply and peel assemblies 50 of generally the samestructure can handle tapes 2 requiring feeding steps which differ inlength from tape to tape. Since the indexing holes 6 are always spacedthe same, from tape to tape, it is only necessary to vary the stroke ofdrive cylinder 2 in order to accommodate different feeding step lengthsdefined by different center-to-center distances between sequentialpockets 4 of a tape 2.

Each interchangeable supply and peel assembly 50 has a tape guide plate53 (FIGS. 9 and 10) which is slidably receivable in a channel 26 (FIGS.5 and 7) of the drive assembly 10. The edges of channel 26 are generallydefined by members 27 and 29 as seen in FIG. 5 and, upon sliding ofguide plate 53 fully into channel 26, a spring metal latch 28 (FIGS. 2and 7) latches onto the body portion of the supply and peel assembly 50to hold it in place. Spring metal latch 28 is easily disengaged by handin order to allow removal of the supply and peel assembly 50 from driveassembly 10.

As seen in FIG. 7, supply and peel assembly 50 comprises a base 52 onwhich is mounted the container 72 for receiving covering material 8after it has been peeled from substrate 3. Base 52 supports lowerpulling wheels 75 rotatably and a pivotal arm 73 which, in turn,rotatably supports upper pulling wheels 74. Upper pulling wheels 74 arebiased into engagement with lower pulling wheels 75 by spring 77 actingon arm 73, and wheels 74 and 75 have intermeshing teeth on theirperipheries. A one-way clutch 78 (FIG. 3) is operatively associated withthe lower wheels 75 and has an eccentricly located pin 80 which isreceivable within slot 84 of peeling drive link 82. Link 82 is slidablyattached to base 52 via slots 86 and pins 87 and is biased to the frontof the device by tension spring 92 connected at one end to pin 54 ofbase 52 and at the other end to pin 90 of link 82. The front or forwardend of drive link 82 has a pin 88 for a purpose yet to be described.

As seen in FIG. 3, the upper wheels 74 have a space therebetween intowhich extends a tape stripper 76 (FIG. 2) to ensure that the coveringmaterial 8 being pulled by the wheels does not get wrapped therearound.Lower tape pulling wheels 75 likewise are spaced and provided with astripper 76.

The front end of base 52 of the supply and peel assembly 50 has theaforementioned tape guide plate 53 affixed thereto, and the reader'sattention is directed to FIGS. 8--10 for the structure of tape guideplate 53 and other members attached thereto. Specifically, a springmetal piece 58 is attached to guide plate 53 and has a locator pin 60depending therefrom which is engagable in an indexing hole 6 of thesubstrate 3, as will be described later. A peeler arm 62 is slidablyattached to guide plate 53 by means of slot 66 and pin 67, and anactuating pin 64 depends from peeler arm 62 through a slot 55 of guideplate 53. The front end of peeler arm 62 supports a laterally projectingguide 68 around which the covering material 8 is guided and reversed indirection when using the feeder. A shutter 70 also projects from peelerarm 62 and is spaced from and slightly forward of cover guiding member68. A stop assembly 63 provides a rearward limit of sliding to arm 62and overhangs the rear end thereof.

Further structural details and functioning of the device will becomeapparent from the following disclosure.

FEEDING AND PEELING

The readers particular attention is directed to FIGS. 12--16 for thisdescription.

After forward indexed feeding of tape 2 by the device, and prior topeeling the cover 8 from substrate 3, shutter 70 is still positioned ata pick-up station (FIG. 12) so as to cover a component 9 which is in apocket 4 from which the cover material 8 was removed in a previouspeeling step. With peeler arm 62 in the position of FIG. 12, coveringmaterial 8 is still covering the next pocket after the pocket which iscovered by shutter 70.

Upon peeling the cover material 8 from this next pocket, peeler arm 62is displaced to the position of FIG. 13 so that shutter 70 uncovers thecomponent 9 situated at the pick-up station for retrieval thereof by avacuum spindle 98 as seen in FIG. 14. With feed pins 38 disengaged fromthe indexing holes 6 of the tape and with substrate 3 restrained bylocator pin 64 as seen in FIGS. 13 and 14, cover material 8 is pulled tothe right and peeled from substrate 3 while causing retraction of peelerguide 68. Retraction of the square motion indexer 33 (to the right inFIG. 14) displaces link 82 against the bias of spring 92 via engagementof one of the arms 37 of the square motion indexing assembly 33 with pin88 of link 82.

One-way clutch 78 is drivingly engaged with lower wheels 75 only whenrotated in the clockwise direction of FIG. 14. Pin 80 of clutch 78 ridesin a slot 84 of link 82 so that displacement of link 82 to the rightagainst the bias of spring 92 causes clockwise rotation of clutch 78which, in turn, rotates lower wheels 75 clockwise. Thus, upper wheels 74are also rotated, and the intermeshed teeth of wheels 74 and 75cooperate to pull on the cover material 8 passing between them so as topeel it from the substrate 3. Peeling guide 68, in turn, is pulled bythe tension on cover material 8 so as to retract arm 62 to the right,along with shutter 70, to the position of FIG. 14. Covering material 8passes around guide 68, between it and shutter 70, with shutter 70 beingsufficiently close to guide 68 that the shutter recloses a pocket as itis being opened by peeling cover 8 therefrom. Thus, shutter 70 isretracted from the pick-up station at which it is positioned over analready peeled pocket (FIG. 12) to the position of FIG. 13 in which thepocket at the pick-up station is uncovered and the next unpeeled pocketis covered by shutter 70.

With the square motion indexing assembly 33 still retracted to the rightin FIG. 14, the feed pins 38 are raised (to the position of FIG. 15)into engagement with the tape indexing holes 6. Simultaneously, thespring metal strip 58 is lifted by roller 40 so as to disengage locatorpin 60 from another tape indexing hole in preparation for feeding thetape 2 forward. As seen in FIG. 15, pin 41 of the square motion indexer33 also is raised so that it will engage pin 64 of peeler arm 62 anddrive peeler arm 62 forward in concert with feeding of tape 2, thusmaintaining contact between peeler guide 68 and cover material 8 duringthe indexed feeding of the tape.

As may be seen in FIG. 11, a piston slide valve 36 has attached theretoan arm 42 for supporting roller 40 and a member 39 for supporting feedfingers 38 and pin 41. Piston 36 is slidably received within cylinder 35which, in turn, is attached to base 34 and slide plate 16. Base 34 isalso provided with inverted L-shaped arms 37 against which springs 46bear to bias member 39, and thus fingers 38 and pin 41, downwardly asillustrated in FIGS. 14 and 16.

With the feeding pins 38 and pin 41 raised to the position of FIG. 15,fluid is provided to the right end of cylinder 22 in order to extend thepiston rod 23 and square motion indexer 33 to the left, with pin 88 oflink 82 remaining in engagement with one of arms 37 under the influenceof spring 92. During tape feeding, one-way clutch 78 is rotatedcounterclockwise (to the position of FIG. 16) by way of pin 80 riding inslot 84 of link 82. However, when clutch 78 is rotated in thisdirection, it is disengaged from peeling wheels 75 so that the peelingwheels 74 and 75 are reversely rotatable by a leftward pull on cover 8during feeding of tape 2. Thus, peeling tension in cover material 8 isremoved during indexed feeding of the tape. In a prototype of theinvention, about half of the length of the covering material 8 which waspushed into box 72 during peeling was retracted back out of box 72during tape feeding in order to relieve tension in the cover material 8that otherwise would be caused by the feeding step.

After feeding tape 2 by the appropriate amount so as to present the nextpocket at the pick-up station, fluid pressure is relieved from the lowerend of slider valve piston 36 so that springs 46 urge the member 39downwardly. Concurrent downward movement of roller 40 allows springmetal plate 58 to engage pin 60 with an indexing hole 6 while fingers 38are disengaged from other indexing holes 6 and pin 41 is lowered frompossible engagement with pin 64, in preparation for another peelingstep. At this time, the position of peeler arm 62 as in FIG. 16 also isillustrated in FIG. 12.

FLUID ACTUATION OF MOVING PARTS

Referring to FIGS. 5 and 11, slider valve piston 36 has a supply orifice362 and upper and lower exhaust guiding slots 364 and 366. Slider valvecylinder 35 has top and bottom exhaust orifices 351 and 354, top andbottom supply orifices 356 and 358, upper and lower middle orifices 352and 353, and an input/exhaust fitting 368 by which fluid is admitted tocylinder 35 in order to raise piston 36 against the bias of springs 46.

The base 34 of the square motion indexer 33 has upper and lower exhausts342 and 344, a forward (extend) supply duct 346, and a reverse (retract)supply duct 348. The supporting slide 16 for the square motion indexer33 is provided with a T-fitting 162, a supply hose 164, and a hose 166to supply fluid to poppet valve 322. Poppet valve 322 (FIGS. 3 and 4)has an actuation button 323 and a hose 324 (FIGS. 1, 4, 6, and 7) fordirecting fluid to pusher pin 32 according to actuation of button 323.

As seen in FIG. 1, drive cylinder 22 has a fitting 224 by way of whichfluid for retracting piston 23 is passed from a hose connected tofitting 45 which, in turn is connected to supply duct 348 of base 34 ofthe square motion indexing assembly. Likewise, piston 23 is extendedwhen fluid is supplied to fitting 222 of cylinder 22 via the hose whichis connected to fitting 44 which, in turn, is connected to duct 346.

In operation, constant air supplied via hose 164 to the bottom ofT-fitting 162 supplies air into slide 16 and to poppet valve 322 viahose 166. Whenever button 323 is depressed, the air to poppet valve 322is diverted to hose 324 to raise pusher pin 32 (FIG. 6). The airsupplied to slide 16 is selectively applied to ducts 346 or 348according to up and down positioning of piston 36 within cylinder 35.Piston 36 is normally biased downwardly by springs 46, as explainedearlier, and is extended upwardly by fluid applied to the bottom ofcylinder 35 through fitting 368. Fitting 368 is attached to a three-wayvalve (not shown for fluid supply to, and exhaust from, the bottom ofpiston 36 according to a timed actuation of the valve. When piston 36 isin the downward position of FIG. 5, air is supplied via holes 358 and353 of cylinder 35 and hole 362 of piston 36 to duct 348 so as toretract piston rod 23 of cylinder 22 and, thus, slide member 16. At thistime, slot 364 of piston 36 provides an evacuation path for exhaust offluid from the other end of cylinder 22, through duct 346, holes 352 and351 of cylinder 35, and exhaust port 342 of base 34.

When piston 36 is raised, fluid will be supplied to duct 346 to extendthe piston of cylinder 22 and thus drive slide member 16 forward, whilethe fluid in duct 348 from the opposite end of cylinder 22 is exhaustedthrough openings 353 and 354 of cylinder 35 via slot 356 in piston 36.Thus, the square motion indexer 33 is driven backward and forward bycylinder 22 according to supply of fluid to opposite ends of cylinder 22and the fluid supply and exhaust, in turn, relies upon the raised orlowered position of piston 36.

As seen in the alternate embodiment of FIGS. 17 and 18, it is alsocontemplated that a spring member 96 may be used to return a similarpeeler guide to the forward, extended position upon relief of tension incover material 8.

The following claims are intended to cover all of the generic andspecific features of the invention herein described and all statementsof the scope of the invention which, as a matter of language, might besaid to fall therebetween.

Now that the invention has been described, we claim:
 1. In an apparatushaving means for feeding a component supply tape step-wise so as topresent components carried by said tape to a pick-up station, saidapparatus having means for changing a feeding step length so as toaccommodate different center-to-center distances between saidcomponents, the improvement comprising:a fluid actuated reciprocatingpiston, the stroking length of which determines said feeding steplength; and said step length changing means comprising a stop means forlimiting said length of stroking.
 2. The improvement as in claim 1, andfurther comprising:means for manually adjusting said stop means from aposition which is accessible to an operator, without requiring removalof said apparatus from its use position.
 3. The improvement of claim 1,and further comprising:means for manually changing said stop meanswithout providing clearance between said apparatus and similar adjacentfeeding apparatus.
 4. The improvement of claim 1, wherein said stopmeans comprises:a physical stop member positionable to change a rearwardlimit of said stroking length.
 5. In a tape feeder having means forfeeding a tape stepwise from a supply so as to present componentscarried by said tape to a pick-up station for retrieval, said tapehaving means for retaining said components on said tape and saidapparatus having peeling means for removing said retaining means fromsaid components sequentially for said retrieval, said apparatus alsohaving means for driving said feeding means and means for driving saidpeeling means, the improvement comprising:a base portion of said tapefeeder comprising said feeding means and said means for driving saidfeeding means and said means for driving said peeling means; asubassembly of said tape feeder comprising said peeling means and aguide for said supply; and means for removably attaching saidsubassembly to said base portion.
 6. The improvement as in claim 5, andfurther comprising:means for adjusting a step length of said feeding. 7.In an apparatus for feeding a tape from a supply and presenting pocketsin a substrate of said tape to a pick-up station for retrieval ofcomponents from said pockets, said tape having a cover enclosingcomponents in said pockets, said apparatus having means for feeding saidsubstrate from a supply to said pick-up station and means for removingsaid cover from said pockets sequentially in order to provide access tosaid components at said pick-up station, said apparatus also havingmeans for driving said feeding means and means for driving said coverremoving means, the improvement comprising:a base to which are attachedsaid feeding means, means for driving said feeding means, and means fordriving said cover removing means; a subassembly to which are attachedsaid supply, means for guiding said substrate to said pick-up station,and means for retaining said substrate in a particular location,relating to said subassembly and along a path of said feeding, betweensteps of said feeding; and means for removably attaching saidsubassembly to said base.
 8. The improvement as in claim 7, and furthercomprising:means for adjusting a step length of said feeding.